The present invention disclosed herein relates to an apparatus for treating a substrate, and more particularly, to an apparatus for adjusting the inner pressure of a process chamber.
Semiconductor fabrication processes are performed in a process chamber. At this point, the inner pressure of the process chamber is controlled to predetermined pressure by a pump that is installed on an exhausting pipe. To this end, opening/closing operations of a valve installed on the exhausting pipe are controlled.
Referring to FIG. 1, a valve 30 moves a plate 31 installed within an exhausting pipe 20 to thereby adjusting the inner pressure of a process chamber 10. The plate 31 may open at least one portion of a passage 21 of the exhausting pipe 20 according to process pressure conditions.
When the plate 31 opens a portion of the passage 21, gas flows through only an open region 21a of the passage 21, and is prevented from flowing through a closed region 21b of the passage 21 by the plate 31. Accordingly, the flow of gas discharged from the process chamber 10 is biased to the open region 21a, whereby gas discharged from the process chamber 10 is biased to the open region 21a, whereby gas within the process chamber 10 unevenly flows. The uneven flow of the gas varies a treated result of a substrate placed within the process chamber 10, according to regions on the substrate.